The protections "impose a real and appreciable impact on students' fundamental right to equality of education," he wrote. "The evidence is compelling. Indeed, it shocks the conscience."

For their part, state and local teachers’ unions quickly joined in a chorus of condemnation of the ruling.

"This is a sad day for public education," said Randi Weingarten, head of the American Federation of Teachers. No student should endure an ineffective teacher, she said, "but in focusing on these teachers who make up a fraction of the workforce, [Treu] strips the hundreds of thousands of teachers who are doing a good job of any right to a voice."

While teacher unions have long argued that tenure protects the best and brightest educators by providing blanket job security, detractors say tenure does as much to protect incompetent educators, keeping them in the system to the detriment of students.

Tenure opponents would argue for a merit system similar to that used by private enterprise which promotes individuals based on merit rather than seniority or tenure. Tenure opponents say getting rid of tenure will allow administrators to weed out incompetency and promote integrity.

The landmark case is viewed as a major loss for teacher unions and an undeniable victory for a Silicon Valley group that brought the case on behalf of nine students. Anti-tenure groups in other states like New York are eyeing the decision and are expected to file similar cases.

On the other hand, state and local teachers’ unions blamed poor management for failing to root out incompetent instructors. At the same time, school systems across America find getting rid of incompetent professors and teachers in public institutions to be difficult if not impossible in many cases.

“When a high-quality junior teacher is laid off instead of a lesser, more experienced colleague, the result is classroom disruption on two fronts," he wrote. It's a "lose-lose situation" that "is unfathomable and therefore constitutionally unsupportable."

The suit was filed against the state of California and the top public officials responsible for the state's education laws which makes it a precedent that will no doubt be followed by legions of tenure opponents in other states.

In summary of the 16-page decision, it marks the end of a process that saw teachers laid off based solely on how long they had worked in the system. It also strips teachers of special treatments involving job security not available to other school or state employees. Currently teachers are awarded tenure after 18 months of employment, making it difficult for administrators to weed out incompetent instructors.

U.S. Education Secretary Arne Duncan described the decision as a national "mandate" to change similar "laws, practices and systems that fail to identify and support our best teachers and match them with our neediest students." He said the welfare of "millions of young people" is at stake.

In addition, the ruling allows that “teachers can be evaluated fairly through a statistical analysis based on student test scores,” another issue teacher unions strongly oppose. Treu cited testimony quantifying how many months of learning a student can lose because of a bad teacher in support of his decision.

"What this continues to do is promote an anti-teacher narrative," said- Joshua Pechthalt, president of the California Federation of Teachers. The ruling will be appealed.